Monday, July 20, 2015

Hummingbirds and the Sugar Fix

Getting on a sugar high -  REK
After a few weeks with little hummingbird action, they are back at our deck battling over the feeders.  While we tend to associate hummers with nectar and sugar water, they get over 25% of their diet as insects.  This is their source of protein and it is especially important while they are raising their young, a time when they almost disappear from our feeders.

The insect diet of hummingbirds includes hawking mosquitoes, gnats, and fruit flies, gleaning spiders, aphids, caterpillars and even insect eggs.

They have been called "nectar powered flycatchers" for good reason.  They consume up to half their weight in sugars daily, both from long tubular flowers seemingly made with them in mind, as well as from tree sap and our feeders.  It takes a lot of energy to maintain 1200 heartbeats per minute and 80 wingbeats per second!  Their sugar slurping is done with a remarkable tongue we discussed in a recent blog.

Hummingbirds are related to swifts, powerful predators of flying insects with a short beak perfect for grabbing their prey mid-flight.  Hummingbirds' beaks extend far beyond their skull, perfect for picking insects off of deep flowers.  On the other hand, grabbing an insect in flight would be like catching a fly with chopsticks.  Recent research described in this PBS video shows that when hawking in mid-air, they gulp down the insect by opening wide and catching it deep in their jaws.

Gleaning a bug from a flower -
Some people raise bugs in a container, using rotten fruit to attract and breed fruit flies.  They then release them at a regular time of day, training the hummingbirds to come by for a dose of protein.  Since we raise lots of gnats and mosquitoes with no effort along Bull Creek, we want our hummers to hunt on their own.

Pennsylvania State University has a good resource page with facts about our common Ruby-throated Hummingbird.